Translation guide
Expresses the process of losing weight or becoming slender. Japanese distinguishes between natural thinness, intentional weight loss, and emaciation.
The speaker actively tries to become thinner through diet, exercise, etc.
The most common verb for losing weight or becoming thin, often implying intentional effort.
最近、痩せたね。
You've lost weight recently, haven't you?
ダイエットで痩せたい。
I want to lose weight by dieting.
Literally 'body weight decreases', a neutral way to say one's weight has gone down.
運動したら体重が減った。
My weight decreased after exercising.
Borrowed from English 'slim', often used in fashion or beauty contexts.
このドレスを着るとスリムに見える。
You look slim in this dress.
The person becomes thinner without deliberate effort, often due to health, stress, or aging.
Also used for unintentional weight loss, context clarifies the cause.
病気で痩せてしまった。
I became thin due to illness.
Focuses on becoming slender in shape, not necessarily weight loss.
年をとると体が細くなる人もいる。
Some people become thinner as they age.
The person becomes extremely thin, often due to starvation or severe illness.
Emphasizes extreme thinness, often with a negative connotation.
難民たちは飢えで痩せ細っていた。
The refugees were emaciated from hunger.
Describes a haggard, gaunt appearance, often from exhaustion or illness.
彼は入院してげっそりした。
He became gaunt after being hospitalized.
Something becomes thinner in dimension, like a book, fabric, or layer.
Used for flat objects becoming thinner, or for density decreasing.
この本は後半で内容が薄くなる。
This book gets thin on content in the second half.
For cylindrical or linear objects becoming thinner.
鉛筆が細くなった。
The pencil became thin.
痩せる is for living things losing weight/flesh. 細くなる is for slender shape (people or objects). 薄くなる is for flat things or low density.
彼女は痩せたが、まだ細くはない。
She lost weight but is not yet slender.
English 'become thin' can be awkward if directly translated as 薄くなる for people. Use 痩せる for weight loss.
✕ 彼は薄くなった。
He became thin. (incorrect for a person)